The present invention relates to a split type seat back composing a seat for a vehicle. More particularly, the present invention relates to an attaching structure of the split type seat back including a pair of seat backs which are independently pivotably attached to a floor of the vehicle.
In the related-art seat 1 for a vehicle shown in FIG. 9, a seat back 2 for supporting the upper body of a passenger and a seat cushion 3 for supporting a hip and thighs of the passenger compose seating spaces of the passenger. In this structure, the seat back 2 and the seat cushion 3 are respectively independently fixed to a vehicle body with each other.
The seat cushion 3 described above is composed as follows. A cushion frame 4 made of material such as resin, the rigidity of which is relatively high is arranged below a cushion made of a flexible material which forms the seating space. Side covers 5 made of resin art attached to both sides of the cushion frame 4 in the vehicle width direction. Here, the cushion frame 4 protects the cushion from a floor face of the vehicle body. At the same time, the cushion frame 4 performs a function of maintaining a shape of the cushion. The side cover performs a function of preventing a passenger from directly touching an edge portion of the frame 4 or a floor face of the vehicle body.
As shown in FIG. 10, the seat back 2 is divided into two portions and arranged in the vehicle width direction. In an upper portion of each seat back 2, the head rest 6 is arranged being capable of moving in the vertical direction. An outer lower end portion and an inner lower end portion in the vehicle width direction of each seat back 2 are pivotably attached to a floor FL by the floor bracket 7 and the center hinge bracket 8 so that the two portions of the seat back 2 can be independently moved with each other. In this case, as shown in FIGS. 11 and 12, in the floor bracket 7 which is used for attaching the outer end portion in the vehicle width direction of each seat back 2 to floor FL, the reclining mechanism 9 capable of adjusting an inclination angle of each seat back 2 is provided. Each reclining mechanism 9 is covered with the outer cover 10 made of resin. Each floor bracket 7 and center hinge bracket 8 are respectively covered with a rear cover 11 and a hinge cover 12. By the rear cover 11, the hinge cover 12 and the outer cover 10, it is possible to prevent a deterioration of the outer appearance which is caused when the floor bracket 7, the center hinge bracket 8 and the reclining mechanism 9, which are made of metal, are exposed. Further, it is possible to prevent a passenger from directly touching these components.
In this connection, in the case where the related-art seat 1 is used as a rear seat for a wagon and no bulkhead is provided between the rear seat and a luggage compartment located behind the rear seat, the following problems may be encountered. As shown in FIGS. 13 and 14, at the time of sudden braking operation, luggage W loaded in the luggage compartment is moved forward by the effect of inertia in the arrowed direction of FIGS. 13 and 14 and collides with the seat back 2. Then, an impact load is given being concentrated onto the center hinge bracket 8 by the moving luggage. Therefore, the center hinge bracket 8 is damaged. As a result, the right and the left back seats 2 are opened like a double door at a division portion.
Therefore, Patent Document 1 proposes a structure for preventing a seat back of a vehicle from being damaged by luggage. In the Patent Document 1, a seat back protection member is protruded at the rear end of the rear seat back of the vehicle in which no bulkhead is provided between the seat back and the luggage compartment.
Patent Document 1: Japanese Patent Publication No. 10-217819A
However, in the structure proposed in the Patent Document 1, the following problems may be encountered. Although a direct collision of the luggage against the seat back can be avoided by the protection member, since the seat back, which is divided to the right and the left, is directly attached to the floor by the bracket, an impact force, which is given from the luggage to the seat back through the seat back protection member acts on the bracket as it is. Therefore, the bracket is deformed and damaged. As a result, there is a possibility that the right and the left seat back are opened at the division portion.
Further, the following problem may be encountered. Since the seat back is not attached to the seat cushion but directly attached to the floor, the seat back protection member obstructs a fixation of the center hinge.